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Busting wireless bottlenecks with Wi-Fi

Wireless operators are turning to Wi-Fi hot spots as they try to alleviate bottlenecks on their networks.

Last month at the Consumer Electronics Show in Las Vegas, I sat in press conference after press conference wanting to pull my hair out in utter frustration, because even though I had 100 percent signal strength on my wireless air card, I could barely load a Web page.

My 3G Sprint air card, which under normal circumstances provides me with a very reliable, stable, and usable Internet connection, slowed to a crawl when I needed it the most. I've had similar experiences at other venues using other wireless networks. At the U.S. Open in New York City this summer, I could barely make a phone call on my AT&T iPhone. And sending or receiving e-mails on my iPhone was unthinkable at peak times of the day during the tournament. Last spring, while attending a Pearl Jam concert in Madison Square Garden, I was also unable to post pictures to Facebook via a Verizon Wireless Motorola Droid.

The reason? In each instance, the network was simply overloaded. At CES, my fellow bloggers and journalists were trying to file their stories at the same time I was. And at the U.S. Open and Pearl Jam concert, thousands of other fans were also making phone calls, uploading pictures, sending and receiving e-mail, downloading apps, and surfing the Web.

The crush of users in one concentrated area, who were all trying to use the network at the same time, was too much for the network to handle. As a result, these networks became practically unusable.

With the proliferation of smartphones and other wirelessly connected devices like tablets, wireless consumers are always connected to the Internet. And in highly trafficked areas like arenas, conferences, train stations, and shopping malls, carrier networks are being stretched to their limits. Wireless operators are deploying new 4G networks using a technology called LTE to help handle the heavy traffic loads, but 4G alone won't be enough. Carriers are also turning to Wi-Fi to offload some of this traffic and prevent network bottlenecks.

"The fact that carriers are moving aggressively toward 4G doesn't negate the need for Wi-Fi, and vice versa," said Niv Hanigal, senior director of product management for Ruckus Wireless, a company that provides Wi-Fi equipment for carrier-grade Wi-Fi networks. "Wi-Fi is the most cost-effective way to deal with some of their biggest pain points in high density areas, regardless of whether they're deploying 4G or not."

A deluge of data
Wireless carriers are expected to see mobile data traffic increase 26 times between 2010 and 2015, according to Cisco Systems' latest Visual Networking Index Forecast. By 2015, Cisco says, mobile data traffic will grow to 6.3 exabytes of data, or about 1 billion gigabytes of data, per month. The data traffic surge is likely to hit carriers hardest in densely populated areas or places where large groups of people congregate.

Why? The answer is simple. Wireless bandwidth is shared across all users in the same cell site. The more people in a given area trying to access the network, the less capacity is available for everyone in that cell site. That means when I was at CES or at the U.S. Open, I was competing for a limited amount of bandwidth with the hundreds or thousands of other people also trying to access the same resources in that same wireless cell site.

Carriers have two immediate options for creating more capacity in high-usage areas. First, they could create smaller cell sites using their licensed spectrum. Second, they could offload some of their most bandwidth intensive traffic onto a higher capacity, less expensive network.

Wireless carriers are creating smaller cell sites where they can, but setting up new cellular towers can be expensive. Wi-Fi is likely their best answer for combating a tidal wave of data traffic heading their way. And here's why. For one, Wi-Fi access points are small and can be mounted almost anywhere. Second, because Wi-Fi is so inexpensive, the technology has found its way into almost every consumer-electronic product on the market, from TVs to laptops to smartphones. In fact, almost every smartphone that is being introduced to the market today has Wi-Fi embedded. This is important because it means there is already a market full of Wi-Fi enabled smartphones that can be offloaded to Wi-Fi when necessary.

And third, advancements in Wi-Fi technology during the past five years have helped make it a more affordable option for building metro-scale networks. The latest version of the technology, known as 802.11n, can travel over much greater distances than previous versions of Wi-Fi. This means that with a single access point, carriers can create Wi-Fi networks that span several city blocks. What's more, these access points can be meshed together to create Wi-Fi "hot zones" that extend networks even further.

The so-called 802.11n Wi-Fi standard also offers much more capacity than older versions of Wi-Fi. For example, previous versions of Wi-Fi known as 802.11 a, b, or g could provide a maximum of 54Mbps in a given hot spot. 802.11n Wi-Fi offers up to 300Mbps per hot spot, Hanigal said.

"Wi-Fi isn't the end all be all for wireless operators," said Jeff Thompson, CEO of Towerstream, which plans to build citywide Wi-Fi hot zones. "It's not going to give carriers 100 percent coverage for their networks, but it can provide a large data oasis where high demand users can be offloaded to alleviate congestion."

Wi-Fi hot zones to the rescue
Wireless operators have already begun to turn to Wi-Fi to help alleviate congestion on their networks. In the U.S., AT&T has been the most aggressive in its use of Wi-Fi. It owns more than 20,000 Wi-Fi hot spots across the country in retail locations, such as Starbucks. It allows its wireless subscribers to use the network for free. The carrier hopes the free access will encourage smartphone and laptop users to log on to a hot spot when it's available rather than use the 3G wireless network.

AT&T has even experimented with Wi-Fi hot zones. In May, the company launched a Wi-Fi network in Times Square that was available for AT&T wireless data customers. AT&T said that some smartphone customers with an auto-authentication client on their devices will connect automatically to an AT&T Wi-Fi hot spot. This client identifies the AT&T hot spot and connects the device without the customer doing anything. AT&T says it has had this capability since 2007. Phones that should be able to connect automatically include the iPhone, several BlackBerry devices, and a select number of Windows Mobile devices, an AT&T representative said.

Still, connecting to a Wi-Fi hot spot is not entirely seamless. I have owned an iPhone since 2008 and have never been able to connect automatically to an AT&T Wi-Fi hot spot. AT&T customers can go to the AT&T Web site to get more information: For many AT&T customers, using AT&T's Wi-Fi is still a manual process the first time they enter a new hot spot. Customers have to log on to the Wi-Fi network and key in a password to be authenticated onto the network. While some Wi-Fi savvy consumers may seek out hot spots, many will not bother.

China Mobile's CEO Wang Jianzhou said this is one of the biggest hurdles that carriers face when it comes to using Wi-Fi to offload mobile traffic.

"Authenticating users on operator hot spots is inconvenient," he said during a speech at the Mobile World Congress in Barcelona last week. "Easy Wi-Fi authentication is essential. "

China Mobile is one of the first wireless operators in the world that will use Wi-Fi in a major way to help offload traffic. Wang said during his speech that China Mobile hopes to deploy 1 million mobile hot spots throughout China in the next three years.

"Operators cannot cope, no matter how much they try to expand capacity with 2G and 3G networks," he said. "Extending Wi-Fi coverage has proved to be a very important supplement to cellular networks. It can effectively alleviate data traffic [congestion]."

Hanigal of Ruckus Wireless, which is providing the Wi-Fi gear that China Mobile is using to build its network, said wireless operators throughout Asia and Europe see the value in building their own Wi-Fi networks in dense areas to offload traffic. But these Wi-Fi networks are not your typical hot spots. They are built and controlled by the carriers, and more importantly they are tied in to the carrier's current wireless network. This will allow users to seamlessly roam on and off the Wi-Fi networks without even realizing that they are on a Wi-Fi network.

The idea is that the device will be able to pick the best available network, whether that's a 3G or 4G cellular network or a Wi-Fi network.

"Carriers aren't just building more hot spots that they can control themselves," he said. "This is about tying Wi-Fi in to the existing wireless networks for billing and authentication, so that when you enter a Wi-Fi hot spot, you're authenticated by the carrier. And the carrier knows that it's you and knows which service plan you have subscribed to."

While China Mobile is building its own Wi-Fi network, in the U.S., Hanigal believes that wireless operators may work with third-party Wi-Fi wholesalers. For example, Towerstream, which has built a business providing wireless data services to large businesses via wireless technology, is starting to build Wi-Fi hot zones in major cities. Using Ruckus equipment, the company built a pilot network in New York City that it has been testing for several months.

Towerstream has built the network so that carriers can seamlessly offload cellular traffic to their Wi-Fi network in high traffic areas, such as Times Square or Grand Central Terminal in New York City. Technology already exists today that will make the handoff between the cellular network and the Wi-Fi network seamless. SmithMicro Software, which already provides mobile VPN solutions for all four major wireless carriers, has developed products that will allow carriers to authenticate and keep track of wireless users as they wander on and off these Wi-Fi networks.

Lee Daniels, senior director of product marketing for SmithMicro, said the real challenge for carriers is tracking customers as they move from their own controlled licensed spectrum environment to the Wild West of the unlicensed Wi-Fi networks.

"Having policy controls becomes very important for the carriers," he said. "They need to have the tools to know when a customer should jump on a Wi-Fi network and when they shouldn't."

Upgrading smartphones to use these offload networks shouldn't be a problem either, Daniels said. Unlike new 4G services that require new chipsets in each device, existing Wi-Fi-enabled smartphones can take advantage of seamless authentication with a simple software upgrade.

Towerstream expects to have its Wi-Fi hot zone network open for business this summer. And the company has plans to offer the service in other major cities as well. Hanigal of Ruckus believes that U.S. carriers will start making more aggressive moves to use Wi-Fi to offload traffic over the next 12 to 18 months. But he said the speed with which they use Wi-Fi hot zones will depend on how painful things get on their 3G networks.

"It will be interesting to see what the iPhone does to Verizon Wireless's network," Hanigal said. "If their 3G network suffers as AT&T's has, then they might turn to Wi-Fi offload more aggressively."

Update 2/26/11 1:25 p.m. PT: AT&T clarified that some smartphones can be automatically authenticated for access to its Wi-Fi hot spots.